The present invention relates to a kind of plate heat exchanger comprising a bundle of several heat exchange plates, which are arranged between a frame plate and a pressure plate and are supported by a lower carrying bar, said lower carrying bar and an upper guiding bar extending through recesses in the lower and upper parts, respectively, of the heat exchange plates, and in particular to a plate heat exchanger in which at least the upper part of each heat exchange plate is provided with at least one lug extending into the upper recess and forming an upper constriction of said recess for retaining the heat exchange plate in position on said guiding bar.
Plate heat exchangers of this kind are common on the market. Generally, one would like to use bars having standard cross-sections, e.g. round bars, both for the lower carrying bar and the upper guiding bar. For this reason conventional heat exchange plates have been provided with U-shaped recesses in both their upper and lower parts. However, to prevent the plates from loosing engagement with the upper guiding bar and the bundle of plates falling apart during assembling or disassembling of the plate heat exchanger, one has been forced after placing of each plate in the heat exchanger to fasten a separately attached bracket on the plate to bridge the upper recess in the plate above the said guiding bar. Alternatively one has had to replace the round bars with specially formed beams cooperating with specially formed recesses in the heat exchange plates, as illustrated in U.S. Pat. No. 2,252,916 and British Pat. No. 1 129 924.
Both these arrangements have proved to be extremely expensive. Therefore, there has been a demand on the market for another solution to the problem as to how the heat exchange plates, while resting on the lower carrying bar, should be fixed relative to the upper guiding bar in order to prevent the bundle of plates from falling apart.